Re: [Shutup] [ietf-smtp] Proposed Charter for the "SMTP Headers Unhealthy To User Privacy" WG (fwd)

Stephen Farrell <stephen.farrell@cs.tcd.ie> Tue, 01 December 2015 22:51 UTC

Return-Path: <stephen.farrell@cs.tcd.ie>
X-Original-To: shutup@ietfa.amsl.com
Delivered-To: shutup@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 7F1D21AD324; Tue, 1 Dec 2015 14:51:31 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.311
X-Spam-Level:
X-Spam-Status: No, score=-4.311 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_PASS=-0.001, T_RP_MATCHES_RCVD=-0.01] autolearn=ham
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id NlrEu26q4GhH; Tue, 1 Dec 2015 14:51:27 -0800 (PST)
Received: from mercury.scss.tcd.ie (mercury.scss.tcd.ie [134.226.56.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 04EE41AD350; Tue, 1 Dec 2015 14:51:26 -0800 (PST)
Received: from localhost (localhost [127.0.0.1]) by mercury.scss.tcd.ie (Postfix) with ESMTP id 0D8A7BE64; Tue, 1 Dec 2015 22:51:24 +0000 (GMT)
X-Virus-Scanned: Debian amavisd-new at scss.tcd.ie
Received: from mercury.scss.tcd.ie ([127.0.0.1]) by localhost (mercury.scss.tcd.ie [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id XZTSsYrYvCXH; Tue, 1 Dec 2015 22:51:23 +0000 (GMT)
Received: from [10.87.48.91] (unknown [86.46.20.32]) by mercury.scss.tcd.ie (Postfix) with ESMTPSA id ABACFBE55; Tue, 1 Dec 2015 22:51:21 +0000 (GMT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cs.tcd.ie; s=mail; t=1449010282; bh=KDTqLNlMxddVhy4q2JWV9+yPKPpMXcR8GCKUXYJAAvc=; h=Subject:To:References:Cc:From:Date:In-Reply-To:From; b=sY6lN+HDyFxkg/3BQ7aYno7ZUPVuCpWlUyNtUk1OHBGPDe/6z9+mokltm7F8SpxgT 6S8jDFekttwfB800uYJsfcdncQFoHjRcrZ7s5TKpR/ZqqGqUjpzjDrNiMwiRwX1Z8z PBlwGZZ4Y2st21wLdodsSMNMlg7U/i0xQEY0Onns=
To: shutup@ietf.org
References: <20151130042819.10658.qmail@ary.lan> <1448858775386-ceecd236-8b11ac04-a03b4438@fugue.com> <glJrvFDUtDXWFA87@highwayman.com> <1448923888960-cb7e590f-f443f8dd-7ec594e1@fugue.com> <565CD58D.9080403@dcrocker.net> <1448924778159-4b16d8e4-631c41b1-52b0fbf2@fugue.com> <605ee74e-863d-47cb-9089-fb83e13e4e38@gulbrandsen.priv.no> <565D9CFC.6070102@pscs.co.uk> <1448988713596-9f0a5014-48bb3a2c-8e1bc938@fugue.com> <565DE53F.2080904@mustelids.ca>
From: Stephen Farrell <stephen.farrell@cs.tcd.ie>
Openpgp: id=D66EA7906F0B897FB2E97D582F3C8736805F8DA2; url=
Message-ID: <565E2461.6000608@cs.tcd.ie>
Date: Tue, 1 Dec 2015 22:51:13 +0000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0
MIME-Version: 1.0
In-Reply-To: <565DE53F.2080904@mustelids.ca>
Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="j3f94Fantq3xsKAk0eM0WBLWrmCkkj5gF"
Archived-At: <http://mailarchive.ietf.org/arch/msg/shutup/nI-Ffu1USm81H8p8MIZACXU_J-M>
Cc: ietf-smtp@ietf.org
Subject: Re: [Shutup] [ietf-smtp] Proposed Charter for the "SMTP Headers Unhealthy To User Privacy" WG (fwd)
X-BeenThere: shutup@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: SMTP Headers Unhealthy To User Privacy <shutup.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/shutup>, <mailto:shutup-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/shutup/>
List-Post: <mailto:shutup@ietf.org>
List-Help: <mailto:shutup-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/shutup>, <mailto:shutup-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 01 Dec 2015 22:51:31 -0000


On 01/12/15 18:21, Chris Lewis wrote:
> 
> On the other hand, we can see that that the lack of that information
> presents difficulties to filtering technologies.  When you get a
> series of harassing emails from a given site originating from a given
> user that's forging from lines and mutating content, you have nothing
> concrete to filter on to distinguish it from other email from the same
> provider.

If you assume the MSA in that case isn't rogue, then there are
a variety of options that could be used in place of the actual
IP address that would have better privacy properties without
being particularly onerous on anyone. For example one could
imagine replacing the MUA IP address value in a Received header
field with something like E(k-epoch, MUA-IP-address) where
k-epoch is some key that changes now and then, perhaps in a
way that requires very little state in the MSA.

The point (for now) is not to recommend that the above be
done but just to note that there are other options that may
not have been considered in the past. Or maybe they were but
the reasonable trade-offs have changed.

Cheers,
S.